U.S. patent number 4,563,170 [Application Number 06/518,449] was granted by the patent office on 1986-01-07 for device for in vivo purification of blood.
Invention is credited to Karl Aigner.
United States Patent |
4,563,170 |
Aigner |
January 7, 1986 |
**Please see images for:
( Certificate of Correction ) ** |
Device for in vivo purification of blood
Abstract
Device for in-vivo purification of the blood, with which blood
pumped from a vein is subjected to intensive ultrafiltration and
the filtrate, together with a quantity of the substitution fluid
volumetrically corresponding to the filtrate, is returned to the
vein, which device combines a double lumen catheter, an inserted,
initial tube pump, and an ultrafiltration filter, with connecting
tubes between catheter and pump. A feed line, with an inserted,
second pump for the substitute fluid, opens into the return line
from the hemofilter to the catheter, and a feed line for
anticoagulants opens into the feed line to the first tube pump; the
ultrafilatration filter is also connected through a precisely
adjustable valve to a measuring container in which the fluid drawn
out of the system is collected. The device is particularly suited
for the filtration of venous blood in intraaterial chemotherapy,
the chemotherapeutic agents, particularly cytostatic drugs, being
filtered out before they reach the heart, so that toxic secondary
effects do not arise.
Inventors: |
Aigner; Karl (6301 Pohlheim,
DE) |
Family
ID: |
6169676 |
Appl.
No.: |
06/518,449 |
Filed: |
July 29, 1983 |
Foreign Application Priority Data
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Jul 30, 1982 [DE] |
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3228438 |
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Current U.S.
Class: |
604/6.06; 604/27;
604/43 |
Current CPC
Class: |
A61M
1/341 (20140204); A61M 5/1582 (20130101); A61M
1/16 (20130101); A61M 1/34 (20130101); A61M
2025/0031 (20130101); A61M 25/0032 (20130101); A61M
1/3615 (20140204); A61M 2205/3331 (20130101) |
Current International
Class: |
A61M
5/14 (20060101); A61M 1/34 (20060101); A61M
5/158 (20060101); A61M 001/03 () |
Field of
Search: |
;604/5,4,6,27,39,43,44 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pellegrino; Stephen C.
Attorney, Agent or Firm: Keil & Weinkauf
Claims
I claim:
1. An in-vivo blood purification system for use in intra-arterial
chemotherapy, said system comprising:
a substantially cylindrical double-lumen catheter insertable into
the vena cava up to the vicinity of the heart and being formed to
provide therein a first channel (B) and, generally parallel
thereto, a second channel (A), each said channel being at least
partially bounded by the wall of said catheter, and the catheter
having a closed tip and a plurality of openings (11) which are
laterally positioned in the vicinity of the catheter tip and
communicate with said first channel (B), and said second channel
(A) terminating with at least two openings (12) in said wall of the
catheter, the distance between the lateral opening (11) farthest
from the catheter tip and the closest opening (12) of the second
channel (A) being not less than 40 mm and not more than 50 mm, and
the opening (12) at the end of the second channel (A) having the
same size as the inner cross-sectional area of said channel
(A);
means (8, etc.) connected to said second channel (A) for pumping
large amounts of blood out of the vena cava through said
channel;
means (1, etc.) for sujecting said blood to ultrafiltration;
and
means (9, etc.) connected to said first channel (B) for returning,
simultaneously with the withdrawal of blood from said second
channel (A), the filtrate to the vena cava through said first
channel (B) together with a requisite amount of substitute
fluid.
2. A system as claimed in claim 1, wherein the ratio of the
cross-sectional areas of the first and second channels is from 1:1
to 2:1.
3. A system as claimed in claim 1, wherein the openings (12) at the
end of the second channel (A) are as large as the cross-section of
the second channel (A).
4. A system as claimed in claim 1, wherein a bulge (13) about 2 mm
thick extends over half of the outer circumference of the catheter
10 between the openings (12) in the catheter wall.
Description
BACKGROUND OF THE INVENTION AND PRIOR ART
The object of the invention is a device for the in vivo
purification of blood, with which blood pumped out of a vein is
subjected to intensive ultrafiltration, the filtrate being
reintroduced into the vein along with a corresponding volume of a
substitute fluid. The device is particularly suited for filtering
out substances introduced in high concentrations in intraarterial
chemotherapy before the venous blood enters the heart and the
systemic circulation.
The ultrafiltration of human blood in the case of kidney failure,
whose object is to achieve a kidney replacement function, is
well-known. The blood is withdrawn from an artery and under its own
pressure is conducted through an ultrafilter or a so-called
hemofilter and the filtrate is returned to a vein, under certain
conditions along with a substitute fluid.
In intraarterial chemotherapy, particularly in the treatment of
tumors, it is desirable to apply the appropriate chemotherapeutic
agents to the area of treatment in the highest possible
concentration. In the past toxicity and other secondary effects
have limited compatability and thus too the maximum possible
dosage.
OBJECT AND SUMMARY OF THE INVENTION
The objective of the present invention is to create a device for
in-vivo purification of the blood which enables large quantities of
therapeutically effective substances introduced in the process of
intraarterial chemotherapy to be filtered out of the venous blood
in order to eliminate toxic effects and secondary reactions.
This objective is achieved by a device for the in-vivo purification
of the blood with catheters, an ultrafiltration filter, a tube
pump, and a tube connection between the catheters, the tube pump,
and the ultrafiltration filter. The device combines
(a) a double lumen catheter (10) with attaching tube connection (8,
9), the tube (8) being connected from the catheter part (A) to the
inlet side of the ultrafiltration filter (1) by way of a first
intermediate pump (2), and the tube (9) connecting the outlet side
of the ultrafiltration filter (1) for the return of the filtrate
with the catheter part (B).
(b) a feed line with a second intermediate tube pump (2a) for
substitute fluid, which opens into the tube connection (9) behind
the filter (1)
(c) a feed line for the anticoagulants, which opens into the tube
line (8) in front of the filter (1), and
(d) the outflow line for the filtrate, which leads from the
ultrafiltration filter (1) through a precisely adjustable valve (5)
and terminates in a measuring tank 6.
To make possible the removal of blood from a vein, a double lumen
catheter with a closed tip is employed. The catheter displays an
initial catheter part with several openings arranged laterally in
the area of the tip, and a second catheter part within the first
part, which second part terminates with 2 or more openings in the
outer wall of the catheter, the distance between the lateral
opening furthest away from the catheter tip and the closest opening
of the second catheter part being not less than 40 mm and not more
than 50 mm.
The catheter has the form of a double tube, the first catheter part
B serving as a return flow tube and the second catheter part A
serving as a suction outlet tube. The sectional area of the two
catheter parts can be of equal or differing size. When the sizes
differ the sectional area of the second catheter part A is smaller
than that of part B. The catheter can be effectively inserted from
the groin into the vena cava inferior, until the catheter tip rests
in the right atrium of the heart. When reintroducing the blood, in
order to prevent disturbances caused by the blood flow which might,
in turn, cause disturbances in the cardiac rhythm, the actual tip
of the catheter is closed and the returned filtrate flows through
several lateral openings.
It is essential that the suction point be no less than 40 mm and no
more than 50 mm from the closest outlet opening.
The venous blood is sucked out with a tube pump or so-called roller
pump and pumped through a conventional ultrafiltration filter under
the increased pump pressure, and the (filtrate) is introduced into
the first catheter part at a volume of 400-500 ml per minute. Since
during filtration 100-200 ml per minute of filtrate fluid
simultaneously leaves the ultrafiltration filter, it is necessary
to counterbalance this loss by introducing a corresponding
quanitity of substitute fluid. To make this possible the tube
connection has an attachment for the substitute fluid, located
between the ultrafiltration filter outlet for the filtrate and the
catheter, a second tube pump being placed in the attachment line to
feed the needed volume of substitute fluid into the system. A line
connected to the filter passes through a precisely adjustable valve
and terminates in a collecting container with a measuring capacity
which volumetrically determines the quantity of fluid drawn out of
the circulation system.
A feed line for anticoagulants, e.g. heparin, opens in the tube
line between the suction tube pump and the catheter. This feed
line, which is about 1 m in length, has an inner diameter of 1.5 mm
and an outer diameter of 3 mm and is attached at its other end to a
precisely adjustable automatic injection mechanism.
The ratio of the free sectional area of the first catheter part B
to the second catheter part A is from 1:1 to 2:1. The inner
diameter of the catheter tube is not less than 3 mm and is
preferably 4 mm, so that the catheter has an outer diameter of
about 4-5 mm.
The outlet openings of the first catheter part B are arranged at
the catheter end over a distance of about 15-20 mm, and the
openings have a diameter of from 1.5 to 4 mm. The openings in the
second catheter part A, or suction tube, which is located inside
the catheter, are preferably as large as the sectional area of the
tube and are positioned at the already indicated distance from the
last feed hole in the outer wall of the catheter. Preferably there
are two suction openings, between which, on the outside of the
catheter wall, there can be a bulge about 2 mm thick, which extends
over half of the outer circumference of the catheter; this
semicircular bulge assures that the suction openings will not be
covered and sealed by the blood vessel wall. The double lumen
catheter is about 60-80 cm long and preferably displays a marking
45 cm from the end of the catheter in order to better control the
inserted length. On the back end of the catheter the two catheter
parts are separated from each other, the first part displaying an
attachment piece about 20 cm long and the second part one about 10
cm long.
The catheter is connected to the tube pump or ultrafiltration
filter by means of tube connections; in front of the behind the
first tube pump, which aspirates the blood and presses it into the
filter, a rubber diaphragm is inserted into the tube connection to
make injections possible, as well as the removal of control samples
with a syringe. Further diaphragms of this type may be placed in
the filtrate line, behind the ultrafiltration filter and in front
of the valve, and in the tube connection for the filtrate to the
catheter. In order to better control the pressure and the filling
of the system, a pillow-shaped tube piece of elastic material can
be positioned between the tube pump and the ultrafiltration filter;
the tube piece enlarges under the pressure produced by the tube
pump, and its increase or diminution in volume provides a scale for
the pressure produced by the pump and for the filling of the
system.
The positioning of a further pillow-shaped tube piece in the tube
line for the filtrate to the catheter is of special advantage for
observation of the degree of filling.
The pillows also function as air bubble traps.
To equalize heat losses caused by cooling within the device, a
preferred embodiment provides for the insertion of a 3-7 m,
preferably 5 m, long spiral tube in the return tube line, the
spiral tube being placed in a water bath with a temperature of
40.degree. C. This makes it possible to heat the filtered blood and
the introduced substitute fluid to the desired body temperature.
The catheter can be produced of conventional materials suitable for
catheters. Such materials have a neutral behavior toward the body
fluid, can be sterilized without difficulty, and are sufficiently
elastic, but also sufficiently rigid and solid to be introduced
into the blood vessels. Suitable materials are polyolefins,
polyfluoridated hydrocarbon polymers, synthetic rubbers, polyvinyl
chloride, and the like. Specially preferred catheter materials are
silicon rubber and implantable polyvinyl chloride. Basically
comparable materials are suitable for the tube connections,
particularly polyolefins, fluoridated hydrocarbon polymers or
polyvinyl chloride. The tube pumps are conventional tube pumps or
so-called roller pumps, in which the pump effect is produced by
compression of the tube.
Conventional ultrafiltration filters, with conventional diaphragms,
are suitable as ultrafiltration filters, to the extent that the
filter area and filter capacity are sufficient to remove the
necessary amount of low-molecular products from the blood. The
necessary filter area is on an order of 1-2.5 m.sup.2, preferably
1.4-2.0 m.sup.2 ; a filter area of 2 m.sup.2 is particularly
preferred. Suitable diaphragms are those that admit substances with
a molecular weight of from 40,000 to 60,000, while blocking
substances with a higher molecular weight. In special cases other
diaphragms can be employed, which admit only low-molecular products
up to a weight of 20,000.
The invention device is particularly suited for use in cytostatic
drug filtration in intraarterial chemotherapy and allows for
systemic treatment with high local concentrations; after taking
effect, the cytostatic drugs and other therapeutically active
substances are filtered out of the blood by means of an
ultrafilter, thus preventing toxic side effects, which particularly
tend to arise when these substances reach the heart with the blood
and then enter the bodily system.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail on the basis of the
illustrations.
FIG. 1 shows a schematic overview of the invention device.
FIGS. 2 and 2a show the form of the catheter;
FIGS. 3 and 3a show a cross-section of the catheter, from which the
arrangement of the second catheter part within the first catheter
part can be identified.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a schematic overview of the invention device, the
connecting tubes 8, 9 of the double lumen catheter shown in FIG. 2
being arranged in such a way that the suction line is attached to
tube 8 and the return line is attached to tube 9. Venous blood is
aspirated by tube pump 2 from the second catheter part A through
connecting tube 8 and pressed through the attached tube into the
ultrafiltration filter 1, to reach connecting tube 9 to the first
catheter part B. In front of the filter 1 the feed line 14 for
anticoagulants opens into the connecting tube 8; the feed line 14
runs from an automatic injection apparatus. Rubber diaphragms 3 are
inserted into the connecting tube 8 in front of and behind the tube
pump 2 to allow injections to be made and control samples to be
withdrawn with hypodermic needles. The same diaphragms are
positioned in the filtrate line between filter 1 and valve 5 and in
the tube line 9 behind the spiral tube 7 positioned in the water
bath.
4 indicates the elastic rubber pillows for filling control. A line
runs from ultrafilter 1 and contains the precisely adjustable valve
5 and terminates in a measuring vessel 6 for collecting the fluid
drawn out of the circulation system. The measuring container is
equipped with an indicator scale and has a capacity of 1-3 liters.
In the connecting tube 9, behind the ultrafiltration filter, there
is a feed point for the substitute fluid, which is fed by a second
tube pump 2a. The tube pump 2a aspirates the substitute fluid from
one or several supply containers of appropriate size attached by
means of connection tubes. If necessary the connecting tube can
contain forks that enable the use of several different substitute
fluids. Pumping of the substitute fluids, which perferably are
so-called Ringer's solutions, is necessary inasmuch as the large
volume of substitute fluid cannot otherwise be introduced into the
system with the desired precision and speed. The output of the
second tube pump 2a is regulated according to the quantity of fluid
leaving the system through the adjustable valve 5, such that a
volumetric loss of fluid is avoided. In principle, however, it is
also possible to introduce smaller or larger quantities of
substitute fluid, if this is required in special cases by the
overall therapy.
To equalize cooling losses a spiral tube 7 is placed in tube line
9; the spiral tube is located in a water bath with a temperature of
about 40.degree. C. This compensates in a simple fashion for heat
losses, allowing the filtrate to be returned to the vein at the
desired temperature after filtration. The connecting tube between
the catheter and the tube pump has a length of about 1.5 meters;
the tube length between the tube pump and the filter is about 1 m,
and about 2 m of connecting tube, without the spiral tube, is
necessary to attach tube 9 to the catheter. The connecting tubes
have an inner diameter of about 5 mm and an outer diameter of about
7 mm.
FIG. 2 shows the double lumen catheter 10 from the side, with the
closed end of the first catheter part B and the lateral openings
11. The second catheter part A, which terminates with the openings
12 in the catheter wall, is located on the inside of the first
catheter part B. The distance C between the opening 12, serving as
a suction opening, and the closest return opening 11 in the first
catheter part B is not less than 40 mm and not more than 50 mm. In
a preferred embodiment there is a semicircular bulge between two
suction openings 12 on the outside of the catheter wall, to prevent
the blood vessel wall from resting on the catheter and to prevent
closing of the suction openings.
FIG. 2a shows a top view of the catheter, with the lateral suction
openings 12 and the return openings 1 of the first catheter part B
arranged at intervals along the catheter point.
FIGS. 3 and 3a show possible embodiments of the fitting catheter
parts A and B, the form shown in FIG. 3 being preferred, in which a
second tube A with a smaller sectional area is arranged inside a
first tube B. The ratio of the sectional areas B:A is preferably
1:1, i.e. the total sectional area of the catheter is twice the
area of the catheter part A. In the embodiment shown in FIG. 3a the
inside of the catheter has a separating wall, which separates
catheter parts A and B.
LIST OF THE REFERENCE NUMERALS
1 ultrafilter, hemofilter
2,2a tube pumps
3 rubber diaphragms
4 soft tubing for optical filling control, tube pillow
5 precisely adjustable valve
6 collecting container for withdrawn fluid (measuring
container)
7 spiral tube in water bath
tube line from catheter
9 tube line to catheter
catheter
11,12 openings in catheter parts
13 bulge
tube line
* * * * *